Is there a random events account?

I think maybe just leave it? If the player is identified via the random event, there's always a way to tap that player with a quick "thanks but no thanks for the event" PM and the option to remove/repost the event elsewhere.

In that case, does the player need to provide a primary account where they can be reached in the case of questions, comments or concerns?

That sounds reasonable enough.

And we could require them to tag their primary account, which turns into a link to their profile (from which a PM can be sent in a single click).